1. The Field of the Invention
The present invention generally relates to the field of light curing devices incorporating light sources and, more particularly, to the field of heat sinks configured for dissipating heat generated by the light sources of the light curing devices.
2. The Relevant Technology
In the field of dentistry, dental cavities are often filled and/or sealed with photosensitive compounds that are cured when they are exposed to radiant energy, such as visible or ultraviolet light. These compounds, commonly referred to as light-curable compounds, are placed within dental cavity preparations or onto dental surfaces where they are subsequently irradiated by a light-curing dental device.
Many light-curing devices are configured with a fiber optic wand for directing light from a light source into a patient's mouth. The light source may comprise, for example, a lamp, a halogen bulb or a light-emitting diode (LED). One end of the fiber optic wand is placed close to the light source so that the light emitted from the light source will be directed into the fiber optic wand. One problem with fiber optic wands is that they are generally unable to capture all of the light that is generated by the light source, particularly light emitted by LEDs, which may be emitted at angles of up to about 120°. Another problem is that fiber optic wands, being essentially solid glass, are relatively heavy and bulky.
One method for overcoming the limitations of fiber optic wands and for generally improving the lightness and efficiency of the light-curing devices is to place the light source(s) of the light-curing device at the end of the light-curing device that is placed next to the composition being cured. Although this addressed problems associated with fiber optic wands, the proximity of the light source(s) to the patient's mouth creates its own problems. For example, heat generated by the light source(s) at the tip of the light-curing device can cause patient discomfort when the tip of the light-curing device happens to come in contact or immediate proximity to the sensitive mouth tissues of the patient. Accordingly, it is desirable to minimize the heat at the tip of the light-curing device.
One method for minimizing the heat at the tip of the light-curing device is to mount the light source(s) on a heat sink that can conduct heat away from the tip of the light-curing device. The ability of a heat sink to absorb and dissipate heat is generally controlled by the material properties and geometries of the heat sink. The arrangement and geometries of the mounting surfaces of the heat sink are also important factors to consider when determining how efficiently the heat sink will be able to absorb and dissipate heat.
Typically, heat sinks are formed of a homogenous material, for example a metal or metal alloy. The material properties that most affect the ability of a given material to act as an effective heat sink are thermal conductivity and specific heat of the material. Heat sink materials may be selected so as to have a high thermal conductivity or a high specific heat. When selecting a material for its high thermal conductivity, the material's specific heat may be lower than desired. Also, when selecting a material for its high specific heat, the material's thermal conductivity may be lower than desired.
It would be an improvement in the art to provide a heat sink formed of a plurality of layers or regions of different materials so as to increase the ability to absorb and dissipate heat.